Telephone system.



C. A. SIMPSON.

TELEPHONE SYSTEM. APPLIOATION FILED 001'. a. 1911. RENEWED 0012,1912.

1,107,37 1 Patented Aug. 18, 1914 ionrrnn s'rn'i ns 'PATENT ennicn.

CHARLES A. SIMPSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO KELLOGG SVVITCHBOARI) AND SUPPLY COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

TELEPHONE SYSTEM Specification of Letters Patent.

Patented Aug. 18, 1914.

Application filed October 6, 1911, Serial No. 653,108. Renewed October 2, 1912. Serial No. 723,589

To all whom it may concern:

.Be it known that I, CHARLES A. SIMPSON, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Telephone Systems, of which the following is a specification.

My invention relates to telephone systems in which service between the different types of lines is established and more particularly to systems in which connections may be established between so-called common battery and local battery substation telephone lines.

An object of my invention is to provide such a system having improved and simplified circuit arrangements which are positive in operation, other features thereof being more particularly pointed out in the following specificationincluding the appended claims.

In telephone exchanges it has been found that the rates charged for different classes of service vary and that a higher rate for one class such as common battery service may be secured, than for another class of service such as the magneto lines, and therefore it is desirable in installing a magneto or local battery system that an. of the telephone lines may be switched rom the one to the other class of service. In switching from one class of service to another it is of great commercial importance that the least possible change be necessary and to this end I have provided a system in which no change of apparatus is necessary but only a few simple changes, in the connection of the line circuit. In providing service to two classes of telephone lines it is also'de;-.

sirable to have link circuits which are unilversal in operation, and to this end I have provide die. link circuit which is adapted for use in interconnecting the two classes of lines and automatically adjusting itself to such two classes of service.

Referring to the'accompanying drawing,

Figure 1 illustrates diagrammatically a circuit arrangement embodying my invention, Fig. 2 illustrates one method of connecting the windings of the cut-0H relay CO when used for common battery service; and Fig. 3 illustrates one method of connecting the windings of the cutoff relay CO when used n magneto line servicc' ductors of the cord circuit.

The system shown thereon includes a loeal-battery substation A connected to line conductors 1 and 2 terminating at exchange apparatus D, and a common-battery substation B connected to line conductors 3 normally out of circuit and a call-hell and condenser normally connected in bridge of the line conductors l and 2 through the normal swltchhook contact. A hand generator is also provided for substation A for signaling the operator at the central otlice. y

The exchange apparatus D of line L and substation A, comprises multiple jacks having their tip and sleeve contacts 6 and 7 respectively connected to the talking conductors of line L and a third contact, ring 8, connected "to a cut-off relay CO. A line relay LR is also provided which is adapted to be operated by the calling subscriber to energize the line signal 9. The line L of substation B terminates in excl'iauge apparatus D which includes apparatus similar to the exchange apparatus D, but differently connected as illustrated in the drawing.

Cord circuit C comprises answering and calling plugs P and I respectively having their tip and sleeve contacts connected by conductors l0 and 11 respectively which have the condensers 12 and 13' interposed. A ringing key R is alsoprovided b ing adapted when operated to connect cur'ent from generator G to the terminals of the called line. A listening key LK is provided, being adapted to connect the 0pcrators telephone with the talking con- A pair of supervisory relays 14 and 15 are provided for the answering end of the cord circuit C and a similar pair 16 and 17 are provided for the calling end of: the cord circuit, Switch ing relays 18 and 19 are connected to the third contact of plugs P and P respectively visory relays.

and are adapted to control the cutting in and out of their associated pair of super- 'such as L but when their associated )lll'I'S are inserted into the jack of a common-battery line such as L, relays 1S and 19 are adapted to be energized. In accordance therewith I make the relays 18, 19 of comparatively low resistance, while the cut-off relays C0 of the local battery lines L are of comparatively high resistance, so that when a relay 18 or 19 is'connected through its plug to the jack and cut-off relay of a local-battery line, suliicient current will flow through the windings of the two connected relays in series to energize the cut-off re lay CO, but not suffieient current to energize the relay 18 or 19 as the case may be, and in practice I find that making the relays 18, 19 ohms resistance and the cutoff relays C0 of the local-battcry lines L of 1000 ohms resistance, such operation of these relays will be secured.

Now as to the cut-off relays C0 of the common battery lines L,.when connection is made with such lines as previously stated the relays 18 or 10. as the case may he, must energize and the cut-oil relays CO also energize. 'Jhcrefore, the cutoff relays C0 of the common battery .lines L are wound to allow su'llicicnt current to flow throu 'h their windin and a rclav 1S or 19, so that both the connected relays will energize, and in practice I have found a resistance of 250 ohms for the relays CO to give a satisfactory operation.

In order that the central office apparatus D and D may be adapted for use in connection with local battery lines such as L and common battery lines such as L, I have arranged the cut-olf relay CO with two wind ings 20 and 21 of 500 ohms each, thus when connected as shown at C0 their total re sistance is 250 ohms, and when using the eutoil"- relay for a local battery line as L, the two windings are connected in series as shown at CO, thus giving a total resistance of 1000 ohms. 'W'ith this arrangement it will be seen that the efliciency of relays CO and CO is maintained and it is only necessary to change the wiring of the. apparatus at D or D in order to accommodate such apparatus for common or local-battery service Any suitable means of connecting the windings of the cut-off relay whereby it may serve as outlined above but in the accompanying diagrams Figs? and 31 have illustrated one method of connecting the termi nals ofthe cut-off relay whereby it may be readily changed for serving: either class of service. In using the cut-off relay for common batt ry service its windings are to be of lit-cl battery lines such as I. or i."

nether. and then to coi'iiiiuctor fit. i3 ith this arrangement the \VllUl'iliQfS 20, are

uected in multiple and otter the low 1 .ance path for operating the switching relays l8, l!) of the cord circuit.

in Fig. 2: have illnstri'itcd cue method of connecting the windings 0. 21 in scric; so that a comparatircly high resistance is oi" fercd to prevent. the operation of switching relays IS, 19 when connected in series with. Assuming a inagi'icto line as l) lad been installed with the cutoff relay connected as in l ig. 3, to change the line ircnit to common battery as indicated at D, it is only l'iccessary to change the windings of the cut oil relay from series to multiple by cutting the connection between terminals Si, 53 and connecting terminals fit), together and terminals 52, 53 together. The winding of line relay LR then disconnected from its armature contact 31 and connected direct to the battery as shown at D, and also the con?- ductor 50 disconnected.

ltctcrring again to the cord circuit C, it will be noted that supervisory relays 14 and 16 have their windings 14' and 16 normally in bridge of the answering and calling ends respectively of cord circuit (1 and as the re lays in or 19 do not energize when counec tion is established with a local battery line such as L, these relays 14 or 16 'hre adapted to be operated by current from the hand generators at the connected substation to control the supervisory lamps and 28. Locking windings H and 16 are provided for relays 14. and 16 to maintain these relays in an energized condition after their armatul'cs are attracted, the locking circuit being controlled from thegrounded contact 24 0t" ltcy 114K.

'hcn connection is established with 0mm nicn battery lincs such as L by either plug l or I, relays 18 or J0 are energized as previously described thus disconn ctin; c: i'isory relay H or 16 and connw'tiug;

thus councctcd are adapted to control snpcrvisory lamps 22, 23.

Referring now to the operators ti lephone 0. this is so arranged that either common a} may be tested to dctcrmine their idle or-busy condition. \Yhen lines I. or l/ are at u'umal without. any plan; connection, the rings 8 or Due to the closing of said contact 38 a maintaining circuit for relay 14 is established by current from battery 25 through Winding 14 alternate Contact 38, conductor 39, to ground at normal contact 24. The closing of contact 38 also causes illumination of supervisory signal 22 by current from battery 25 througl'i -la1np 22, normal contact -10 to the grounded contact 38. The ope atojr noting the illumination of the two supervisory lamps i22--2l 3 Withdraws plugs P and P, thereby restoring the relay 19 causing elftaceinent of signal 23 and thereafter operates key LIX to interrupt. the circuit for re lay 14 allowing said relay to restore, the in terruption of the contact 24 also extinguishing the lamp 2). Also upon withdrawal ot plugs l and l cutott relays (f0 and Ct) are tleenergizetl, restoring the substation control of line relays; LR and LR".

Aasuming now that a connection is to be established between a calling common-hat tery line and 21 called locahbattery line and that the wall in initiated at suhstation ll the subeeribed thereat by removing his reeeiver from it: J \\'ll(l1llfl0l( establishes a circuit for line relay L l over a path traeed from hattery 25 winding of relay' Tilt, n rmal eontact 2t), eonductor 4 suhetation ll returrinn over conductor 3 and normal r-ontart 1 to ground 'lt-SPUHFIlVS to the energ' :ation of relay LR its alternate contact 43 in elosed, thereby establishing a circuit for lanip i) which is lighted hr current from att r) 25"". The operator thereupon inserts ant l'el'lllg plug: P into the ansuerin g jzutlc 5 t line L thereby connecting: the talking strands of the word ircuit (l and line l/ and also eoni'iertiug the winding: of relay; IR and (0' in series. Due t the, l w r1"- sislanre path for eurrent through relay (,(l an prerioualy desrriheal, said relay and re lay 18 are energized by current from hattery L r the enere'ization of relay Ct) disconnectinf: relay LR Whieh restores, canning the etl'aeement of line signal 0. The (nergizin tion ot' relay 18 discount-eta the relay l4 and connerts the windings of relay 15 in bridge of the talking conductors of the an swering end of the cord circuit (3. As at this time. substation ll has its receiver removed from its mvitchhoolt', th re w ll he it path for current over the callingline through the wiudinga of re la 13, causing it to enersize and interrupt its rtmtaet lti preventing! the lighting; of lamp 2:2. The operator having aseertniurd the irantx ot' the ailing suberriher in the usual manner and finding that connection desired with the line of auhstatiou slit will ini-ert rallin; plus: I" in the iaelc of the wanted line IA. therehy connecting the talking: olnluetors of the cord and line rirt-uits an hefore .\l o upon said ennnerlion relay and eonneeted in series and due to the high resistance of relay Ct) SttlllCltlllI current does; not flow through tire coil of relay 19 to cause its energization, but relay CO is energized removing the exhalation control of line relay LR. Due to the failure of relay 19 to energize, the winding 16 of relay i remains connected in bridge of the calling end of cord circuit; (.1 to he actzati'ul hy the eallerl sulmeriher at L-uhwta-i i t for dis-- t-onneetion, The operat r urn-r ortua't 1 the ringing key in the 1mm? nmuneito operate the hell of the called me or lion. 'lhe wi led suhscriber at A. thereupon rerntwee his rereiver from its smitehhooit without any 0* feet upon any t' the central liir'e apparatus at this time. The enllin e, lgltlll tll l3 and oalled soletation A. are i: W eonneeted for rorivorautiein talhing warrant t r substation ll being supplied lion: l it .J through the windings of relay i .l ia hin" wirrfi'nt tor called substution A home suppled from the local battery ther Alter the suhacriheh have finished conersation, the eubeeriher at ll by replaeing hiq reeeii'er upon it,\ r-\\lttl)luulii interrupts the circuit for finite! ry r lay l allowing it to reFtore therein (losing its: wntart l6 and causing! the il iuni iati n ot :zupervirory lamp The called Mil -rih r at A alt r replacing his ieceiwonrratt his hand tftlltrnltu ellecting utrfliillt t'i of relay in in a manner similar to the operation oi" relay 14 as prerioual'v flraewlhed, reh 10 thereby closing its alternate ontact *5? (W tahli hinn a maintaining eircuit for itself and caus ng the illumination of lamp lay urrent from lnitterr 2'1 tlimueh i AJ1 lamp and normal routa fit aln -rnat ite t to? to around at lit operator not ng the il euperviswry Sign plugs l and l tr n: and thereafter artuatw restoration of relay ti signal The \rithdravzl causes the restoration of relays l8 and t the re toration (it the r t-on relay plat-lug the line relay lily! under control of substation ll, while the roster ll'm l8 interruptt. the eireuit for loan ternate con act ettacing t he As previously stated, the r eirruit (l is adapted fo universal e nnertzon l'etrw; the lines of ditl'er ut rlza Filttll l and L, so that it i :ilm rapahhu making eonnertiom as filled. ot heing used for establnhi "'tl tm between two local hatter his 7 "h al. in which case neither relay l1 it? in tn re'ixrd and both ot the it ur lmr x relay, ll and \yi i. we; m et 'terl jerk? h y lili, (Hu it q the and the etl'acenn nt of of plug l? from jack 5 i 011., L El R'S in bridge i3. main lzllllil HM i zrgzilimlig ir 3331i m (Illli', lai' runncviinzi wnnwlinn with said lines. a pair of $115.1

pvrx'isory relays for the answering end 05 Silili (JUl'li rircuit, a switching relay for said i'l h virvuit for connecting either one of said inlays in bridge of the talking strands of the (will vii 'uil', 21ml means whereby said swiiich- 70 inn inlay is or i not nperaiell acrorrling: m iii char-mini" of the (willing line when mnnan-Linn is 1mm? ilxeru'vitli, to opuriiliw v win: ii the wq'vervisory rel 1 i' (in: nri uveringzfwill of said l'illii vi! w i. :2 wifuning Ul'lil) comm-ml t0 :1 il'lll'll wirniluwiur of the plug For col'inm'ting El ar mm 05 will. relays in bridge of the inlivng btnmilea of the link circuit, in aims wliwchy will SWltiflllllQ: relay is or not operated S5 m-r-nwling to the then actor of the calling line when conne'ction is made therewitln to opemtiwly assnrinr e fine of the supervisor rel'iwiv; '0. In the talking): strands of the link virru and a signal (Ol'ltlOllfllllQ by either ine 94:

g '1 for will link nircuit, a 5W1 10 mg \ln v l'm' Slllll link circuit for cmmsv. J (iliif' m" will relays in bridge.) of the talli v j z =nn i-z in ih- (Ol'll vircuit. Szii l swi rrlny wing m apteil to be cunne iorl n :h Put-nil r liiy when connection is V 5 w wz "rc r' nni'oiiwl ljy onc of suit] relays nunlc with :1 local but- Hui in' two of sun] rcn wiicu in liizhli with 2i (ioni- 'cuil; tor int r- ,(f'H'li cir uit conimwixocv r lugw nnl n t -i uitli cncli until il com-ti H in iiaiiilc with {1 pin- 1o lino and by the 1 v rclnys and said ii wnmi iuni is: made with a tcly lino.

t m comprising conil circuitfor intcrrcuit llllV- i rclui' i lii 'il" H- curli cm xuin rriwrv in: of iii ii till} mm M .w niigi'nctic mtlcry or mngnoto' t an, i

c- 5 il.l urc ow lion with ;L lino incl; by :vunl con:

sponding to each pair of supervisory relays and :nluptcil to be controlled according to the circuit conncrtions of thc line connected with whereby thc corresponding supervisory relay is ronncctcrl in Upcrntive relation with the line,

H. A tclcphonc sybtcin comprising nmgucio :lllll cHlHm H liuttcry liuc lino circuits l'oi Hliil lincs c mprning line and cut'oti rclui rn tli circuit conncction of thc cut-oil rcll hcing; :uluptml to lie vnric l according to {ll-(7' iciritcil linc, and n universal cord circuit, to; intcrconinw-tiug :-:ni l linen having two supcrriwry rclny; tor ucli cud. one 120- ing 2 aluptml for u--c with :1. nmgnoto line and the othcr for uszc with :1 common bnttcry line, nrnl u thinl rcluy for cncli cud of the (H1 circuit mlnptcil to be connected in circuit with tho cutoff rclny when connection nnnlc with :1 line and (lillcrcntly operative according to thc conncctions ot the connected cut-oti !cli l'or rclnlcring the propcr suipcrvitor v rciny ctlcctivc.

15. A lclcphouo grstcin comprising lino circl'iitn having linc :nnl cubotl rcluys, the cut-off r rrlnys hcing adapted to in? lill'crcntlv ('(?Iil'l0 "l(ti in cirtoit to minor the linc for mugncto or common lmtt ry :il'YlFQ, uinl a (Uiti circuit for cxtcinlinp th circuit of fifiitl line; having two bupcn'isory relays one i=1 usc for each character of service,

uiiuiitcil and u Witrhing rein rililicrontly opcratiio uccortling; to thc cHtFotl rciny conncctionn of the. line conncctctl with \vlicrcby only the proper supervisory rcluy is rcinlcroii cll'ectivc.

iii. A

c rcni ltltpimlit \'s+tom comprising line lHUllltl lino and out-oil rcluys. jacks for Sititl lincm :i circuit conncction including :1 inch and cutuifi rclny of lflt'l] linc circuit, i1 (")Hl circuit for (anointing thc circuit of Hllll iin n including :1 switching rcluy, menus for moving tlic rcsiutuncc of tin: snirl cut-off rcluji' circuits to min said linc circuits for umgmtn or common niitcry ccri'icc, connectiomv \ilnyi'cliy n cutwrli rclny null switching rclny :21 conncctcd in circuit upon conncc tion with u lino jack by sail cord circuit, Hilltl 'itcl'iiin; rcluy l-cing o n-rnlile only upon su h comm-lion with ono typc of linc circuit hut; .enirl cut oil rclny living opcrublc irrc-pH-tiw: oi" .lic msstnn c of the snitl cir- I Mi said SYVitChlIlg relay being npcmlflc Bill" upon connection with unc type of lim- ('i"i'\ibut Saul cntml'f relay being (ipniziliin spective of the: resistance of its w: Him

18. A telephone system compnr circuits having cutoff relays, lzkilif:

line a circuit including jack am? relay for each line circuit, will in extending the circuit of said in r a. switching relay. means for any in sistance of said cnt nfi' relay ifiYCUllS l said line circuits for magnum or battery service, cnnnectvii WlHTClW a, all relay and switching ml 4 in circuit upon mini'wctinn win; iii-s ml, by said cord Circuit, 321113 FWltCllil 1P3 n.

ing operable nnly upnn 311F111 cnnncMl-J one type (If line en mi: llill lay being OPQI'fiblQ irres jumi ance of the said circuit. in .ncctml,

lines, a univcrsai cnnl circni for inter m 3 

